1. Field of the Invention
Polymers and polymer blends containing, as a copolymerized constituent, an unsaturated dicarboxylic acid anhydride (such as maleic anhydride); and more particularly to methods of stabilizing the same to reduce splay and streaking during molding.
2. Description of the Prior Art
U.S. Pat. No. 4,433,086 (Harris I) recognizes the tendency of polymers containing maleic anhydride to decompose at high temperatures. Harris stabilizes the polymer with a tetrahalogenated aromatic dicarboxylic acid or anhydride.
U.S. Pat. No. 4,397,975 (Harris II) is directed to the same problem but uses a different stabilizer, such as an organic sulfonic acid.
U.S. Pat. No. 4,387,191 (Dufour et al) controls crosslinking in maleic anhydride/acrylonitrile containing polymer by the use of an acid ester of phosphorous acid, such as di-(2-ethyl-hexyl) monoacid phosphate.
U.S. Pat. No. 4,661,545 (Bruls et al) relates to a molding composition containing styrene and maleic anhydride together with a stabilizing amount of an organic phosphite ester.